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[PULL,30/45] target/ppc: Fix rlwinm on ppc64

Message ID 20200317100423.622643-31-david@gibson.dropbear.id.au
State New
Headers show
Series [PULL,01/45] pseries: Update SLOF firmware image | expand

Commit Message

David Gibson March 17, 2020, 10:04 a.m. UTC 
From: Vitaly Chikunov <vt@altlinux.org>

rlwinm cannot just AND with Mask if shift value is zero on ppc64 when
Mask Begin is greater than Mask End and high bits are set to 1.

Note that PowerISA 3.0B says that for `rlwinm' ROTL32 is used, and
ROTL32 is defined (in 3.3.14) so that rotated value should have two
copies of lower word of the source value.

This seems to be another incarnation of the fix from 820724d170
("target-ppc: Fix rlwimi, rlwinm, rlwnm again"), except I leave
optimization when Mask value is less than 32 bits.

Fixes: 7b4d326f47 ("target-ppc: Use the new deposit and extract ops")
Cc: qemu-stable@nongnu.org
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Message-Id: <20200309204557.14836-1-vt@altlinux.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 target/ppc/translate.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)
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Patch

diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 36fa27367c..127c82a24e 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -1938,15 +1938,17 @@  static void gen_rlwinm(DisasContext *ctx)
         me += 32;
 #endif
         mask = MASK(mb, me);
-        if (sh == 0) {
-            tcg_gen_andi_tl(t_ra, t_rs, mask);
-        } else if (mask <= 0xffffffffu) {
-            TCGv_i32 t0 = tcg_temp_new_i32();
-            tcg_gen_trunc_tl_i32(t0, t_rs);
-            tcg_gen_rotli_i32(t0, t0, sh);
-            tcg_gen_andi_i32(t0, t0, mask);
-            tcg_gen_extu_i32_tl(t_ra, t0);
-            tcg_temp_free_i32(t0);
+        if (mask <= 0xffffffffu) {
+            if (sh == 0) {
+                tcg_gen_andi_tl(t_ra, t_rs, mask);
+            } else {
+                TCGv_i32 t0 = tcg_temp_new_i32();
+                tcg_gen_trunc_tl_i32(t0, t_rs);
+                tcg_gen_rotli_i32(t0, t0, sh);
+                tcg_gen_andi_i32(t0, t0, mask);
+                tcg_gen_extu_i32_tl(t_ra, t0);
+                tcg_temp_free_i32(t0);
+            }
         } else {
 #if defined(TARGET_PPC64)
             tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32);